【摘要】：蠕墨鑄鐵是一種綜合性能十分優(yōu)良的鑄鐵材料,不僅具有近似球鐵的力學(xué)性能,同時(shí)具備近似灰鐵的鑄造、減震和導(dǎo)熱等性能。近年來隨著研究的不斷深入,蠕墨鑄鐵在汽車等重工業(yè)行業(yè)有著不可替代的作用。但采用現(xiàn)有的灰鑄鐵加加工生產(chǎn)線對蠕墨鑄鐵件進(jìn)行機(jī)加工時(shí),出現(xiàn)了崩刃、打刀、加工精度不夠等一系列的機(jī)加工問題,而目前國內(nèi)外對蠕墨鑄鐵機(jī)加工困難的問題卻沒有很全面的研究。本課題是結(jié)合中國一拖集團(tuán)有限公司在缸體用蠕墨鑄鐵材料的研究開發(fā)中所使用的爐料、可選擇的蠕化劑種類、合金化元素等方面開展研究,試探索爐料、蠕化劑、合金元素和鐵水過濾等對蠕墨鑄鐵加工性能的影響。本文主要研究在不同工藝條件下蠕墨鑄鐵的顯微組織及加工性能,分為有無過濾對比、蠕化劑種類對比、時(shí)間靜置對比、添加合金元素對比、不同爐料對比以及不同強(qiáng)度鑄鐵加工性能對比和相同強(qiáng)度不同種類鑄鐵加工性能對比。每組對比研究中都用萬能拉伸試驗(yàn)機(jī)進(jìn)行拉伸試驗(yàn)來測得其抗拉強(qiáng)度、屈服強(qiáng)度和延伸率。用布氏硬度計(jì)測得其布氏硬度。用光學(xué)顯微鏡并參照國標(biāo)對石墨形態(tài)和珠光體含量進(jìn)行評級。用掃描電鏡來觀測珠光體的片間距大小。用動靜態(tài)應(yīng)變儀來進(jìn)行標(biāo)定和切削力大小的測定。從而來分析蠕墨鑄鐵的材料及工藝因素對組織及切削加工性能的影響。試驗(yàn)結(jié)果表明:添加過濾網(wǎng)后,能顯著提高蠕墨鑄鐵的蠕化率,優(yōu)化組織。能有效提高以Z14鐵為主要爐料的蠕墨鑄鐵的抗拉強(qiáng)度和布氏硬度,并減小斷面敏感性,但切削力略微增大。而對以高純生鐵為主要爐料的蠕墨鑄鐵的性能基本上無影響。與蠕化劑FeSi RE15Mg3相比,使用蠕化劑FeSiRE6Mg6能獲得更高的蠕化率和更小的斷面敏感性。且以高純生鐵為主要爐料的蠕墨鑄鐵使用蠕化劑FeSiRE15Mg3,抗拉強(qiáng)度達(dá)到400 MPa,但蠕化率較低,而使用蠕化劑FeSiRE6Mg6不僅蠕化率高、斷面敏感性小,抗拉強(qiáng)度也達(dá)到350 MPa。隨著Cu、Sn合金元素的復(fù)合添加,鑄鐵的斷面敏感性都明顯降低。以高純生鐵為主要爐料的蠕墨鑄鐵能獲得較高的蠕化率、珠光體含量、抗拉強(qiáng)度和布氏硬度,但切削力也顯著增大。而以Z14鐵為主要爐料的蠕墨鑄鐵非常容易灰鐵化,因此不適宜采用復(fù)合添加Cu、Sn合金元素的方法來提高其力學(xué)性能。隨著靜置時(shí)間的延長,鑄鐵試樣的斷面敏感性會顯著增高,而切削力都略微降低。以高純生鐵為主要爐料的蠕墨鑄鐵仍能保持80%以上的蠕化率、抗拉強(qiáng)度也在330 MPa。而以Z14鐵為主要爐料的蠕墨鑄鐵易灰鐵化。鑄鐵的抗拉強(qiáng)度和切削力沒有嚴(yán)格的對應(yīng)關(guān)系,鑄鐵的石墨形態(tài)和珠光體含量對抗拉強(qiáng)度和切削力都有一定的影響,但石墨形態(tài)對抗拉強(qiáng)度的影響更加顯著,而基體中的珠光體含量對鑄鐵切削力的影響更加顯著。珠光體含量和珠光體片間距決定了布氏硬度值大小,是影響鑄鐵材料切削力大小的主要因素,且對布氏硬度的影響與對切削力的影響具有相同的趨勢。
[Abstract]:Vermicular graphite cast iron is a kind of cast iron with excellent comprehensive properties. It has not only similar mechanical properties to ductile iron, but also similar properties to gray iron, such as casting, shock absorption and thermal conductivity. When machining vermicular iron castings in the production line, a series of machining problems have appeared, such as edge breaking, knife cutting, inadequate machining accuracy and so on. At present, there is no comprehensive study on the problem of vermicular iron machining difficulties at home and abroad. In this paper, the effects of furnace charge, creeping agent, alloy element and hot metal filtration on the processing properties of vermicular graphite cast iron are studied. The microstructure and processing properties of vermicular graphite cast iron under different processing conditions are mainly studied. The tensile strength, yield strength and elongation were measured by universal tensile testing machine in each group of comparative studies. Graphite morphology and pearlite content were graded by optical microscope and reference standard. The spacing of pearlite was observed by scanning electron microscope. The dynamic and static strain gauge was used to calibrate and measure the cutting force. The microstructure and cutting process of vermicular graphite cast iron were analyzed. The experimental results show that the creep rate and microstructure of vermicular graphite cast iron can be significantly improved and the tensile strength and Brinell hardness of vermicular graphite cast iron with Z14 iron as the main burden can be effectively improved, and the section sensitivity can be reduced, but the cutting force is slightly increased. Comparing with the vermicularizing agent FeSiRE 15Mg3, the vermicularizing agent FeSiRE 6Mg6 can obtain higher vermicularizing rate and lower section sensitivity, and the vermicularizing agent FeSiRE 15Mg3 for the vermicular cast iron with high purity pig iron as the main burden can reach 400 MPa in tensile strength, but the vermicularizing rate is lower, while the vermicularizing agent FeSiRE 6Mg6 not only has higher vermicularizing rate. With the addition of Cu and Sn alloy elements, the cross-section sensitivity of the cast iron decreases obviously. The vermicular graphite cast iron with high purity pig iron as main burden can obtain higher vermicularity, pearlite content, tensile strength and Brinell hardness, but the cutting force also increases significantly. Vermicular graphite cast iron with high purity pig iron as main burden can still keep more than 80% vermicularity. The graphite morphology and pearlite content of the cast iron have certain influence on the tensile strength and cutting force, but the graphite morphology has more significant influence on the tensile strength and the matrix. The pearlite content and the distance between pearlite sheets determine the Brinell hardness, which is the main factor affecting the cutting force of cast iron, and the influence of pearlite content on Brinell hardness and cutting force has the same trend.
【學(xué)位授予單位】：河南科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TG250

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 鄭冰;任鳳章;李鋒軍;張旦聞;熊毅;魏世忠;;Sn對蠕墨鑄鐵顯微組織和切削加工性能的影響[J];鑄造;2016年02期

2 任鳳章;張旦聞;吳銳;王宇飛;孫娟;魏世忠;;材料加工性能評價(jià)中的切削力測量問題的實(shí)驗(yàn)研究[J];材料熱處理學(xué)報(bào);2014年S1期

3 李川度;俞旭如;孫中民;;大型鑄件過濾技術(shù)的應(yīng)用研究[J];現(xiàn)代鑄鐵;2014年02期

4 趙靖宇;呂燁哲;孫玉福;王謙謙;司光東;吳越;丁麗平;李路;;錫對蠕墨鑄鐵顯微組織和力學(xué)性能的影響[J];鑄造;2013年10期

5 鄧幫喜;張志成;周建江;;HX型氣缸蓋蠕墨鑄鐵銑削應(yīng)用研究[J];常州信息職業(yè)技術(shù)學(xué)院學(xué)報(bào);2013年02期

6 肖麗麗;任鳳章;李鋒軍;張旦聞;吳銳;孫娟;王宇飛;;灰鑄鐵不同合金化同等強(qiáng)度下的加工性能對比研究[J];鑄造技術(shù);2012年05期

7 ;2010年全球鑄件生產(chǎn)統(tǒng)計(jì)報(bào)告[J];中國鑄造裝備與技術(shù);2012年02期

8 易力濤;劉金海;李國祿;劉長起;李寅國;楊兆禹;王磊;;衰退對蠕墨鑄鐵熱分析曲線特征的影響[J];現(xiàn)代鑄鐵;2011年05期

9 張伯明;;蠕墨鑄鐵在發(fā)動機(jī)上的應(yīng)用[J];汽車與配件;2011年02期

10 陳杰;;欣特卡斯特推出蠕墨鑄鐵生產(chǎn)過程控制系統(tǒng)[J];汽車與配件;2010年39期

相關(guān)會議論文 前1條

1 王翔;王成勇;鄭李娟;熊偉強(qiáng);;不同冷卻方式對蠕墨鑄鐵車削性能的影響[A];2015年第五屆全國地方機(jī)械工程學(xué)會學(xué)術(shù)年會暨中國制造2025發(fā)展論壇論文集[C];2015年

相關(guān)碩士學(xué)位論文 前2條

1 王超厚;基于軟測量技術(shù)的刀具磨損在線檢測系統(tǒng)研究[D];南昌大學(xué);2008年

2 屠志戀;基于融合技術(shù)的嵌入式表面質(zhì)量檢測系統(tǒng)的研究[D];浙江工業(yè)大學(xué);2006年

，

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